Print PDF from Android Webview

i have android webview contain order mobile web app (asp.net)

everything is fine except when i open pdf file :

    string UrlForAndroid = "HTTPS://docs.google.com/gview?embedded=true&url="+openurl;
    this.Page.Response.Redirect(UrlForAndroid, true);
    this.Page.Response.End();       

it is opened but when i try to print it return blank page, even i press share

however i already set access read & write to external